Battery charger



FIG. 1 is a perspective view of a battery charger showing our new design;

FIG. 2 is a top view thereof;

FIG. 3 is a right side view thereof; and,

FIG. 4 is a bottom view thereof.

The battery charger portion shown in broken lines is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a battery charger, as shown and described. 